Part 15: Test and Disorders for Primary Hemostasis

150-450 × 10^9

Normal value for platelet count

<100, 000

Is the most common cause of clinically important bleeding

Phase Contrast Microscope Method

Reference method for platelet count described by Brecher and Cronkite

1:100 with 1% ammonium oxalate

EDTA whole blood is diluted _______with _____________

15 minutes

In WBC count, 10 minutes is the charging time of the hemocytometer, for platelet________

7 to 21 cells per 100x field

A normal blood smear should approximately ________

Normal

Platelet estimate: 200, 000-400, 000

Low normal

Platelet estimate: 150, 000-199, 000

Slight decrease

Platelet estimate: 100, 000-149, 000

Moderate decrease

Platelet estimate:50, 000 to 99, 000

Marked decrease

Platelet estimate: 0 to 49, 000

Slight increase

Platelet estimate: 401, 000 to 599, 000

Moderate increase

Platelet estimate: 600, 000 to 800, 000

Marked increase

Platelet estimate: Above 800, 000

20-25

Examination of a Wright-stained peripheral blood smear provides estimate of platelet numbers. Using 100x (oil) immersion in the areas of erythrocytes just touching each other, the upper limit of the number of platelet seen per field should not exceed:

a. 10 to 15

b. 15 to 20

c. 20 to 25

d. 25 to 30

200 × 10^9/L

If 10 platelets are seen per oil immersion field, what is the approx. platelet count?

a. 50× 10^9/L

b. 100× 10^9/L

c. 150 × 10^9/L

d. 200× 10^9/L

Light-Transmittance (Optical) Platelet Aggregometry

Method used for platelet aggregometry designed to test PRP

BSS (Bernard-Soulier Syndrome)

Normal response to ACE (ADP, collagen, Epinephrine)

Glanzmann’s thrombasthenia

Normal response to Ristocetin

Whole blood with saline

Specimen used in Lumiaggregometry

PRP

Specimen used for platelet aggregometry

Plt count, Platelet function test, Coagulation test

Vascular disorder are normal in what tests?

Bleeding time and Rumple-Leede test

Vascular disorders are abnormal in what tests?

Rendu-Osler-Weber Syndrome

Hereditary Hemorrhagic Telangiectasia is also known as

Hereditary Hemorrhagic Telangiectasia

Most common inherited vascular bleeding disorder characterized by localized dilation of capillary walls (skin and mucous membranes)

Ehlers-Danlos Syndrome (Cuts Hyperplasia)

Hyperextensible skin, hypermobile joints, laxity, fragile tissues, subcutaneous hematoma formation

Henoch-Schonlein Purpura (Allergic Purpura)

Most commonly seen in children damage to endothelial cells characterized by gastrointestinal hemorrhage and joint swelling

Vitamin C

Scurvy is a deficiency of Vitamin ____

Scurvy

Characterized by defects in the synthesis of collagen and hyaluronic acid

Quantitative with Increased Platelet Destruction

Quantitative or Qualitative: HUS, DIC, ITP, TTP

hit (Heparin Induced Thrombocytopenia)

Plt disorder where platelets are activated by heparin-dependent IgG antibodies against a complex of heparin and PF-4

Reactive lymphocytosis

aka secondary thrombocytosis characterized by moderately increased plt count

Autonomous Thrombocytosis

aka Primary Thrombocytosis

Essential Thrombocythemia

an example of MPN (Myeloproliferative Neoplasm) characterized by uncontrolled proliferation of bone marrow megakaryocytes; platelet count exceeding 1 million/uL

GP Ib/IX/V

Primary platelet surface receptor for vWf

BSS and vWD (Bernard Soulier Syndrome and von Willebrand’s disease

Platelet adhesion disorders

Type I

Most common/ mildest form of vWdisease

von Willebrand’s disease

Most common congenital bleeding disorder

Platelet adhesion

Platelets adhere to a foreign surface

Platelet aggregation

Platelets adhere to other platelets

Glanzmann’s thrombasthenia

Deficiency of GP IIB/ IIIA

Fibrinogen

Ligand for GP IIB/IIIA

Hereditary afibrinogenemia

Absence of fibrinogen in the blood

Alpha and Dense Granule Deficiencies

Storage Pool Diseases

Gray platelet syndrome

Considered as the only alpha granule deficiency

PF-4 and B-thromboglobulin

In gray platelet syndrome, plasma levels of ________ are increased

CTAD

Anticoagulant used for Gray Platelet Syndrome

Quebec Platelet Disorder

Results from a deficiency of multimerin ( a protein stored in granules)

WAS (Wiskott-Aldrich Syndrome)

The inheritance pattern of all dense granule deficiencies above is Autosomal Recessive, except for ___________

X-linked recessive

Inheritance pattern for WAS (Wiskott-Aldrich Syndrome)

Trauma-induced coagulopathy

What is the most common acquired bleeding disorder?

a. Trauma-induced coagulopathy

b. Vitamin K-deficiency

c. Liver disease

d. vWd

C

All of statements below regarding Glanzmann’s thrombasthenia are correct, except
1) It is a rare autosomal recessive disorder

2) It occurs with lesser frequency than BSS

3) This disorder demonstrates normal clot retraction

4) This disorder shows normal platelet count and normal platelet morphology

5) A prolonged bleeding time result is expected in a patient with this condition.

a) 3,4 and 5

b) 3 and 4

c) 2 and 3

d) 1, 3 and 4